<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      var name = 222
      var a = {
        name: 111,
        say: function () {
          console.log(this.name)
        }
      }

      var fun = a.say
      fun()
      a.say()

      var b = {
        name: 333,
        say: function (fun) {
          fun()
          // fun.call(window)
        }
      }

      b.say(a.say) // 222
      b.say = a.say

      b.say() // 333
      // b.say.call(b)
    </script>
  </body>
</html>
